Crane structure for bicycle pedal

ABSTRACT

An improved crane structure for a bicycle pedal wherein the front outer thread has a same rotary direction with the inner thread hole in the crane, and the rear outer thread has the opposite rotary direction with the front outer thread; the inner thread rotary direction disposed in the cylindrical sleeve is the same as that of the bolt protruded from a pedal, and the edge of the two each has two holes, so that after the front outer thread of the cylindrical sleeve is secured to the inner thread hole in the crane and a nut is used to lock the rear outer thread in order to limit the rotation, the bolt of the pedal is then locked onto the inner thread of the hole of the cylindrical sleeve for the assembling in order to attain the effects of securely mounting and easily detaching the crane structure.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to an improved crane structure for a bicycle pedal, more particularly to a crane structure having a cylindrical sleeve in an inner thread hole of a crane and two threads respectively disposed at a front section and a rear section on the outer periphery of the cylindrical sleeve and substantially in opposite rotary directions with each other to respectively limit the screw connection of the inner thread of the crane and the nut in order to attain the effects of securely mounting and easily detaching the crane structure.

[0003] 2. Description of the Related Art

[0004] In general, a bicycle A provides a crane C for coupling a pedal B as shown in FIG. 1A. In the figure, a hole is disposed each at a front section and a rear section of the crane C, and the hole at the front section is coupled with an axial rod A1 of the bicycle body, and the inner thread hole C1 at the rear section is coupled with a bolt B1 protruded from the pedal B by a screw in order to provide a pedaling movement by the rider's legs. However, the entire body of the present bicycle emphasizes on light weight. Therefore, traditional steel material is no longer adopted, but the light weighted aluminum alloy material is used instead, and such material also applies to the crane C naturally. However, the crane made of aluminium alloy material is unable to stand the strong force exerted on the inner thread hole C1 at the rear section of the crane C, and thus manufacturers usually install a wear-proof cylindrial sleeve D onto the inner thread hole C1 in the crane C. An outer thread D1 formed on the outer periphery of the cylinidrical sleeve D has the same rotary direction with the inner thread hole C1 in the crane C; and an inner thread D2 formed on the inner wall has the same rotray direction with the bolt B1 protruded from the pedal B, such that after the outer thread D1 on the surface of the cylindrical sleeve D is secured into the inner screw hole C1 of the crane C as a whole, the inner thread D2 on the inner wall of the outer thread D1 is coupled with a bolt B1 protruded from the pedal B (as shown in FIG. 1B) to strengthen the stability of connecting the crane C with the pedal B with the assembling of the cylindrical sleeve D.

[0005] Although such method can attain the purpose of strengthening the resistance to shocks and vibrations, it also causes the cylindrical sleeve D to loosen and fall off due to the shocks and vibrations produced when the bicycle is running on an uneven road surface. Therefore an improved commection method as shown in FIG. 2 was suggested. After the cylindrical sleeve E is coupled, the end section E1 is spread out to attach onto the outside of the inner thread hole C1 of the crane C to constitute a positioning after the cylindrical sleeve is installed, but such method may damage the inner thread E2 at the end section E1 of the cylindrical sleeve E, and cause the bolt B1 protruded from the pedal B unable to be fully screwed for the connection.

[0006] In summation of the above description about the prior art that needs a breakthrough, the present inventor herein enhances the performance than the conventional method by performing a series of researches and developments to overcome the shortcomings of the prior art and finally succeeds to invent the present invention and file an application for this invention.

SUMMARY OF THE INVENTION

[0007] The objective of this invention is to provide an improved crane structure for a bicycle pedal, comprising a cylindrical sleeve disposed in a thread hole of a crane and two outer threads substantially in the opposite rotary directions to each other disposed at the front and rear sections of the outer periphery of the cylindrical sleeve; wherein the outer thread at the front section has a same rotary direction with the inner thread hole in the crane, and the outer thread at the rear section has the opposite rotary direction with the outer thread at the front section; the rotary direction of the inner thread disposed in the cylindrical sleeve is the same as that of the bolt protruded from a pedal, and the edge of the two each has two holes, so that after the outer thread at the front section of the cylindrical sleeve is secured to the inner thread hole in the crane and a nut is used to lock the outer thread at the rear section in order to limit the rotation, the bolt of the pedal is then locked onto the inner thread of the hole of the cylindrical sleeve for the assembling. The outer threads produced at the front and rear sections of the outer periphery of the cylindrical sleeve so produced are in the opposite direction to each other to respectively limit the screw connection of the thread hole in the crane and nut in order to attain the effects of securely mounting and easily detaching the crane structure.

[0008] To make it easier for our examiner to understand the objective of the invention, its structure, innovative features, and performance, we use a preferred embodiment together with the attached drawings for the detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, in which:

[0010]FIG. 1A is a perspective diagram of the disassembled parts of the structure according to a prior art.

[0011]FIG. 1B is a cross-sectional diagram of the assembled parts of the structure according to a prior art.

[0012]FIG. 2 is a cross-sectional diagram of the assembled parts of the structure according to another prior art.

[0013]FIG. 3 is a perspective diagram of the disassembled parts of the present invention.

[0014]FIG. 4 is a cross-sectional diagram of the assembled parts of the structure according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Referring to FIGS. 3 and 4, an improved crane structure for a bicycle pedal according to the present invention comprise a recession 111, 112 respestively disposed on both sides of the opening of an inner thread hole 11 in a crane 1 for installing a cylindrical sleeve 2 and a nut 3, and two outer threads respectively disposed on a front section and a rear section of the periphery of the cylindrical sleeve 2 and substantially in opposite rotary directions with each other. In other words, the outer thread 21 at the front section of the cylindrical sleeve 2 has a rotary direction same as that of the inner thread hole 11 of the crane 1 (it is a left thread for the crane on the left side), and the outer thread 22 (such as a right thread) at the rear section has a rotray direction opposite to that of the outer thread 21 (such as a left thread) at the front section, but has a rotary direction (such as a right thread) same as that of the nut. The inner thread 23 disposed in the cylindrical sleeve 2 has the rotray direction (such as a right thread) with that of a bolt 41 protruded from the pedal 4. The right crane and the left crane have opposite directions, and the edge of the cylindrical sleeve 2 and the nut 3 each has two holes 24, 31 for providing a tool to pass through for the screwing.

[0016] By securing the outer thread 21 at the front section of the cylindrical sleeve 2 into the inner thread hole 11 of the crane 1, the cylindrical sleeve 2 is located in the recession 111 at the opening of the inner thread hole 11 in the crane 1, and the outer thread 22 at the rear section is located in the recession 112 at the opening of the inner thread 11 in the crane 1 for securing a nut 3 onto the outer thread 22 in the recession 112 to limit the positioning. A bolt 41 of the pedal 4 is then secured onto the inner thread 23 in the hole of the cylindrical sleeve 2 for the assembling (as shown in FIG. 4). Such arrangement not only allows the cylindrical sleeve 2 to have a stronger shock absorbent, but also prevents the crane 1 from being loosened once the bicycle is riding on an uneven road surface, since the two outer threads 21, 22 respectively disposed at the front and rear sections of the outer periphery of the cylindrical sleeve 2 have opposite rotary directions. When the cylindrical sleeve 2 is loosened from the inner thread hole 11 of the crane 1, the cylindrical sleeve 2 and the nut 3 are rotating in opposite directions to tightly connect the two parts. Therefore, the cylindrical sleeve 2 will not be secured too tight or too loose or even fall out.

[0017] If we need to replace the cylindrical sleeve 2, the two holes 24, 31 at the edge of the cylindrical sleeve 2 and the nut 3 can be used to pass a tool for the screwing operation, which can save the trouble of looking for other tool to remove the cylindrical sleeve 2.

[0018] In summation of the above description, the present invention herein enhances the performance than the conventional structure, overcomes the shortcoming of the prior art, and further complies with the patent application requirements and is submitted to the Patent and Trademark Office for review and granting of the commensurate patent rights.

[0019] While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that the invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation and equivalent arrangements. 

What is claimed is:
 1. An improved crane structure for bicycle pedal, comprising: a cylindrical sleeve disposed in a thread hole in a crane; two outer threads substantially in opposite rotary direction to each other, respectively disposed in a front section and a rear section of an outer periphery of said cylindrical sleeve, wherein said outer thread at the front section being in the same rotary direction with that of the thread hole in said crane, and said outer thread at the rear section being in the opposite rotary direction with that of the outer thread at the front section, and the rotary direction of the inner thread disposed in said cylindrical sleeve being the same as that of a bolt protruded from a pedal; two holes disposed on each edge of said cylindrical sleeve and said nut for letting a tool to pass through and rotate; after the outer thread at the front section of said cylindrical sleeve being locked into the inner thread of said crane and the outer thread at the rear section being locked by a nut to limit the rotation, a nut of a pedal being locked into an inner thread in a hole of said cylindrical sleeve for the assembling, such that the outer threads at the front and rear sections of the outer periphery of said cylindrical sleeve being in opposite rotary directions with each other and respectively limit the screw connection of the inner thread of said crane and the nut in order to attain the effects of securely mounting and easily detaching the crane structure. 